interesting article, for all those who think Ubuntu is already easy

[Derek Broughton]

Scott James Remnant wrote:

> On Tue, 2006-05-30 at 13:46 -0300, Derek Broughton wrote:
> 
>> Very funny.  It would still be a lot simpler if you'd explain _why_ udev
>> shouldn't do this.  Despite Matt's equally dismissive message - it's not
>> even true that it _doesn't_.  udev is entirely capable of assigning
>> names, and does routinely (my Palm - by default - becomes /dev/pilot, and
>> only udev is involved in that).
>> 
> Because nobody should care what the device node in /dev is called --
> it's a session thing, and changes each time you plug in the device.

We've agreed time after time that we _don't_ care about the dev names!  I
realize that I've been laboring under a misapprehension - the documentation
as I read it says nothing about udev _only_ creating symlinks within /dev
but tests seem to show that it can't set SYMLINK= from anywhere else.  We
could have avoided a lot of this if you'd just mentioned that, instead of
harping on the fact that we shouldn't care about /dev - which we agreed
with all along.  Even so, udev can call a script, and I _still_ think I
could make udev do what Alan asked within that script.  Why would I want
to?  To keep it out of the desktop, for one thing - as Alan pointed out,
this is an application needed by users who don't use Gnome, KDE or perhaps
even any desktop at all.

> The desktop translates the connected device list into a useful set of

But how does "the desktop" know a device is connected?  udev notifies hal
and hal either notifies or is polled by the desktop, right?  udev is still
involved.  Excuse me if my terminology isn't accurate enough for you, but
you're not helping things by dismissing our suggestions without explaining
yourself.

> icons and selections for the users, named appropriately (e.g. "NEC
> DVD-ROM") etc.

They're _not_ always named appropriately.  You still haven't explained how
to differentiate between two memory sticks, or iPods, etc.  Alan's
suggestion of having the "OS" ask is reasonable - whether that's at the
desktop or udev level.
 
> btw, incidentally, the /dev/pilot thing doesn't work most of the time --
> it links to ttyUSB0 when it should link to ttyUSB1, and there's no way
> to do that with udev

A slight modification of the rule to ignore all the even device numbers
would work: 
KERNEL=="ttyUSB[13579]", SYSFS{product}=="Palm Handheld*", \
                                        SYMLINK+="pilot"
(the device assigns two consecutive tty devices, but the odd one is always
the one you want pilot-link to use).  In any case, I mentioned it only
because you and Matt both said udev doesn't do this, when it clearly does.  

btw:
> For those people without UI, they can use udev TODAY
> to assign a persistent name to that device; dapper ships with this
> already -- e.g. I can use /dev/disk/by-id/ata-LITE-ON-COMBO* to access
> the CD-RW/DVD-ROM etc.

works only for hardware with a serial number (and possibly not at all
for /dev/scd*), which for some reason my NEC CD/DVD writer doesn't seem to
expose.
-- 
derek